Alkylthio-caranones

ABSTRACT

There are provided novel mercapto- or alkylthio-substituted oxoterpenoids having 10 carbon atoms in the terpenoid skeleton. These novel compounds may be acyclic monocyclic or bicyclic. The novel compounds are useful as odorants particularly, but also for producing aromas, e.g. of a vegetable note.

United States Patent [1 1 Lamparsky et al.

1 ALKYLTHIO-CARANONES [75] Inventors: Dietmar Lamparsky,

Wangen-Dubendorf; Peter Schudel, Grut near Wetzikon, both of Switzerland[73] Assignee: Givaudan Corporation, Clifton, NJ.

[22] Filed: Apr. 26, 1974 [21] Appl. No.: 464,262

Related U.S. Application Data [62] Division of Scr. No. 69,457, Sept. 3,1970, Pat. No.

Kendall et a1 260/586 R [451 July 15,1975

2,586,306 2/1952 Copenhauer 260/586 R 3,723,531 3/1973 Tobias 260/586 R3,820,975 6/1974 Poje et a1. 260/586 R 3,845,134 10/1974 Helmlinger eta1. 260/586 R Primary Examiner-Leon Zitver Assistant Examiner-NormanMorgenstern Attorney, Agent, or F irmThomas Cifelli, Jr.

[5 7] ABSTRACT There are provided novel mercaptoor alkylthiosubstitutedoxo-terpenoids having 10 carbon atoms in the terpenoid skeleton. Thesenovel compounds may be acyclic monocyclic or bicyclic. The novelcompounds are useful as odorants particularly, but also for producingaromas, e.g. of a vegetable note.

2 Claims, No Drawings ALKYLTHIO-CARANONES This is a division ofapplication Ser. No. 69.457 filed Sept. 3, 1970, now US. Pat. No.3,819,712.

RELATED APPLICATIONS This application claims priority from Swissapplication No. 13748/69 filed Sept. 10, 1969.

FIELD OF THE INVENTION Novel aromatizing agents I SUMMARY OF THEINVENTION The present invention is concerned with new mercaptooralkylthio-substited terpenoids of the general formula R representshydrogen or together with R represents a CC bond,

R represents hydrogen or together with R represents a dimethylmethylenegroup, or, when R is isopropyl, together with R represents a C-C bond,

R" represents hydrogen or together with R represents a dimethylmethylenegroup,

R represents hydrogen or together with R represents a CC bond,

R represents hydrogen or, when R signifies isopropyl, together with Rrepresents a CC bond,

R represents isopropyl or together with R or with R represents adimethylmethylene group,

R represents methyl.

X represents a CC double bond taking the place of a CC single bond,

in to 2,

Y represents oxo bound to a primary or secondary Catom and Z representsmercapto or lower alkylthio located in the ,B-position to the carbonylfunction,

provided that when R R and R represent hydrogen, R represents isopropyl,R together with R represents a C-C bond, Y is B to the carbon atombearing the substituent R m=0, Z is a to the carbon atom bearing thesubstituent R and ,8 to the carbon atom bearing the substituent R, thenZ represents alkylthio, their use as odorants and/or flavourings, aswell as a process for their manufacture.

The above formula I includes mercaptoor alkylthiosubstituted acyclic,monocyclic or bicyclic monoterpenes each containing a carbonyl group,the mercapto or alkylthio substituent Z being located in the B-positionto the carbonyl function.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Formula I, as also all otherformulae appearing in the description and the claims, is meant toinclude all stereoisomers.

The above formula I includes the compounds of the following generalformulae as sub-groups X Y x x I-l I-2 x Xu Y X -3 I- J I-5 thecompounds of formulae I-1 and I-2 claiming particular interest.

In formulae I-l to I-5, X, Y, Z and m have the significance statedabove.

The compounds [-1 are acyclic and have a carbon skeleton like, forexample, citral or tagetenone. The compounds I-2 are monocyclic and havethe pmenthane skeleton. The compounds I-3, I-4 and I-5 are bicyclic anddisplay the skeleton of pinane, thujane or carane.

By lower alkylthio in the sense of the above definition are meantalkylthio residues the alkyl portion of which is straight-chain orbranched and preferably contains up to five C-atoms; examples of suchalkyl residues are: methyl (preferred) ethyl, n-propyl, iso-propyl,n-butyl, sec. butyl, tert. butyl, amyl, etc.

The double bonds represented in the above formula I by X can be locatedin any position of the molecule, thus, for example, in the ring and/orin the side-chain in cyclic systems. These optionally present doublebonds are located between two adjacent C-atoms which are bound to otheratoms solely by single bonds.

A primary C-atom in the sense of the above definition is present in thegroup CH a secondary C-atom in the group Cl-I The new terpenoids ofgeneral formula I are distinguished by specific aroma and/or odorantproperties, especially by berry, spice and vegetable notes, for examplein combination with the underlying terpenoids. They can accordingly beused for the aromatisation of foods and delicacies as well as of drinksor as odorants for the manufacture of odorant compositions such asperfumes, or can be used for perfuming technical products, for example,solid and liquid detergents, synthetic washing agents, aerosols orcosmetic products of all kinds (e.g. soaps). These compounds can be usedin perfumery because of their intensive green notes. The compounds withZ equal to SH are distinguished by particularly good tenacity. Theodorant compositions utilizing these novel compounds, for exampleperfumed products, can contain a wide proportional range thereof, from0.005 to 5.0% by weight may be used.

It is to be understood that the scope of the present invention does notinclude naturally occurring compounds of general formula I.

The novel compounds of formula I can be used in a wide variety ofaromatized products. Because of their berry-like aroma properties, thesecompounds can be used for producing aroma in foods (e.g. milk drinks,yoghurt, etc.), in delicacies (e.g. confectionery products such asbonbons, soft ice, etc.) and in drinks (e.g. mineral waters). They canalso be used as aroma enhancers for enhancing the aroma of vegetable,soup and snack food aromas where cabbage-like or onionlike aromas areespecially desired. Their marked flavourous qualities make use in smallconcentration possible. A suitable dosage comprises the range of 0.01ppm to 100 ppm, preferably of 0.1 ppm 1 ppm, in the finished product.

The new compounds of general formula I can be obtained in accordancewith the invention by reacting a compound of the general formula.

wherein R to R, X and Y have the above significance and n 1 to 3, adouble bond represented by X being located in the a, B-position to thecarbonyl function or being isomerisable into this position, with acompound HZ (wherein Z signifies the same as above) in the presence of abase under anhydrous conditions, provided that where R and R arehydrogen, R together with R represents a CC-bond, Y is B to the carbonatom bearing the substituent R R where present is hydrogen and R isisopropenyl or isopropylidene, n 1, then HZ is a lower alkylmercaptan.

As bases there come into consideration, for example: inorganic bases,for example alkali metal hydroxides such as sodium hydroxide orpotassium hydroxide, alkaline earth hydroxides such as, for example,calcium hydroxide, organic bases, for example amines such as alkylamines(e.g. diethylamine or triethylamine), heterocyclic amines such aspiperidine etc.

By a double bond isomerisable into the oz, B-position to the carbonylfunction is meant that double bond in the molecule which is capableunder the influence of bases at elevated temperature of migrating intothe desired a, B- position from another position (e.g. ,8, 'y-position).

The reaction of the starting compounds of general.

formula II in the presence of the said bases is expediently effected inthe presence of a solvent. Suitable solvents are, for example, alcoholssuch as alkanols (e.g. methanol, ethanol, isopropanol, ethanol beingpreferred), or ethers such as diethyl ether (preferred), or diisopropylether.

However, if desired one can also work in the absence of a solvent,especially when the starting material of formula II is brought toreaction with a lower alkylmercaptan. The reaction temperatureexpediently lies between about 0C and 100C; a range between about 40 and60C is preferred. The duration of the reaction depends on the reactiontemperature. For example it amounts to about 2 hours for a reactiontemperature of 40 to 60C.

The reaction of the present invention can also be initiated by theprovision of a free radical initiator, suitably ascaridol or a, a'-azobis isobutyronitrile.

The reaction can be carried out at normal pressure or expediently atelevated pressure (e.g. 10 atm.), since the reaction proceeds withreduction in volume.

The proportion of the starting compound of general formula II to thesulphur compound HZ can be varied within wide limits; preferably, atleast 1 mol of sulphur compound HZ is used per mol of starting compoundI]. The sulphur compound HZ can, however, also be used in excess.

The reaction of the starting compound II with the sulphur compound HZ isexpediently initiated by treating the starting compound II or thesolution of this starting compound in an anhydrous solvent with thesulphur compound HZ in the presence of a base (which can be added assuch or dissolved in one of the above-named solvents) at a temperaturebelow the boiling point of the sulphur compound HZ and heating themixture to the reaction temperature in a suitable pressure vessel.

New asymmetric centres can result by the reaction of the startingcompound II with the sulphur compound HZ, and consequently the reactionproduct can be obtained in the stereoisomeric forms thereby possible.

The reaction product can be isolated from the reaction mixture accordingto conventional methods; for example, by distilling off the solvent, ifnecessary, filtration of elementary sulphur which was formed from theresidual mixture and fractional distillation, by which means the productcan be separated from unreacted starting compound II.

In the following Examples, the temperatures are stated in degreesCentigrade.

EXAMPLE 1 15.2 g of piperitone are dissolved in 30 ml of absolute etherand treated with 1.0 g triethylamine. The solution is cooled to ca Atthis temperature, a total of 5 ml of hydrogen sulphide is condensed inin the course of an hour, the solution initially colouring yellow andlater depositing a red-yellow precipitate. After completed HS-condensation, the reaction product is rapidly transferred into anautoclave, rinsed with 50 ml of absolute ether and allowed to stand for29 hours. The

pressure rise during the gradual heating to room temper'atureis veryslight, so that a pressure-resistance of the apparatus of 10 atm. lssufficient. The solution is thereupon filtered and concentrated. Theresidue 16.9 g) is fractionally distilled in vacuum. After removal of7.8 g of unreacted piperitone there are thus obtained 1.6 g ofp-menthane-l-thiol-3-one of boiling point 5759/0.05 mm Hg, n 1.4932. inthe form of two stercoisomers in the ratio 1:4. (Thecis-p-menthane-lthiol-3-one can be separated from the trans-pmenthane- 1-thiol-3-one gas-chromatographically Odour of the product: sulphurous,minty, reminiscentof rhubarb, but also suitable for cassis andblackberry notes.

EXAMPLE 2 g of carvone are treated with a solution of 1 g of KOH in 100ml of absolute ethanol. H- S is condensed into the solution, cooled to75, until ca ml of H 8 are condensed. After standing overnight in anautoclave at room temperature, the mixture is heated to 50 for 2 hours(in so doing, the pressure rises to 8.5 atm.), then cooled, taken up inether, the ethereal solution washed with saturated NaCl solution, driedand concentrated. The residue (14.3 g) is fractionally distilled invacuum. The distillate (6.3 g) of boiling point 7778, n 1.5248 to1,5229, contains, besides ca 10% of unreacted starting material, amixture of stereoisomeric p-menth-S-ene-6-thio-2-ones' in the ratio ofca Odour: Green with sulphurous note, reminiscent o thyme and roastonions.

EXAMPLE 3 15.2 g of citral (mixture of geranial and neral) are dissolvedin 50 ml of absolute ether and treated with l g of triethylamine. Themixture is cooled to 70 and 10 ml of hydrogen sulphide are condensed in.After decanting into a pressure vessel, the reaction mixture is allowedto stand overnight at room temperature and then it is heated to 50 for 2hours. After cooling and removal of the ether, in the residue, only alittle citral can still be detected besides the reaction productobtained.

Odour: intensive, long-lasting, reminiscent of"rhubarb.

EXAMPLE 4 15.2 g of pulegone are treated with 0.5 ml of triethylamineand cooled to ca 0 by means of an ice-common salt mixture. Withstirring, methyl mercaptan in excess is condensed into the mixture and,after condensation of 200% of the calculated amount, the mixture istransferred into an autoclave. After standing overnight at roomtemperature, the reaction mixture is heated to 50 and, after cooling ofthe autoclave, the reaction product immediately distilled in vacuum. 9.8g of 8-methylthio-p-menthan-3-one are obtained as a clear liquid withpleasant odour reminiscent of peppermint, geranium and caraway, boilingpoint 7273/O.l5 mm Hg, n 1,4982. The yield amounts to 73% of the theorybased on reacted pulegone. The two stereoisomeric compounds8-methylthio-cis-p-menthan-3-0ne and 8- methylthio-trans-p-menthan-3-oneobtained can be separated gas-chromatographically.

EXAMPLE 5 15.2 g of piperitone and 0.5 g of triethylamine are cooled to-5. 15 ml of methyl mercaptan are condensed in with stirring. Themixture is treated and.

worked up as in Example 4. By fractional distillation, unreactedpiperitone is distilled off from the reaction mixture, and thel-methylthio-p-menthan-3-one enriched to 95% content (boiling point88l0.1 mm Hg, n,, 1.4990). The yield amounts to 6.2 g or 48% of thetheory, based on reacted piperitone. The odour of the product isreminiscent of dill and caraway as well as of boiled white cabbage.

i EXAMPLE 6 15.0 g of carvone are mixed with 0.5 g of triethylamine. 20ml of methyl mercaptan are condensed in this mixture at roomtemperature. After standing overnight in the autoclave, the mixture isheated to 50C for a further 2 hours. After removal of the excess methylmercaptan, the reaction product is fractionally distilled in 'vacuum.After a small fore-run of urireacted carvone,

there are obtained 14.9 g of 6-methylthio p-menth-8- en-2-one in theform of a mixture. of two isomers in the ratio 1:4 (boiling point l05-107/0.2 mm Hg, n 1.5067 corresponding to a yield of 78% of the theory.The odour of the mixture is reminiscent of boiled white cabbage with acaraway and onion peel note.

EXAMPLE 7 l5.g of citral and 0.5 of triethylamine are treated withmethyl mercaptan as described in Example 6. After removal of the excessof methyl mercaptane, there is obtained a practically citraI free crudeproduct (16 g) which after distillation yields. besides a polymericresidue, 10.4 g of 3,7-dimethyl-3-methylthio-6- octenal, correspondingto a yield of 52% of the theory (boiling point 8284/O.2 mm Hg. n51.4961). The odour of the compound is reminiscent of kohlrabi andcauliflower with a slight citral note.

EXAMPLE 8 Into a suitable autoclave there are charged 90 g of3-caren-2-one, 0.3 of triethylamine and 4 drops of ascaridol. Theautoclave is cooled to -20 and 10 ml of methylmercaptan distilledthereinto. The autoclave is sealed permitted to-stand overnight at roomtemperature and subsequently warmed to 50C for 2 hours. The reactionmixture is fractionally distilled to yield 4- methylthio-Z-carone (2.8g) in the form of 2 stereoisomers having a boiling point of 80-85C at0.1 mm, n 1.5210.

The odor of the compound is green and earthy. The resulting aroma isvegetable like and is also reminiscent of the aroma of the tonka bean.

EXAMPLE 9 In accordance with the procedure of Example 7 verbenol isreacted with methylmercaptan to yield l-methylthioverbanone, boilingpoint at 0.1 mm Hg, n 1.5080 (product of 70% purity).

EXAMPLE 10 In accordance with the procedure of example 7 myrtanal isreacted with methylmercaptan to yield 2-methylthio-myrtanal, boilingpoint 76 at 0.3 mm Hg, n 1.5170. This product contains as an impurity l0of a by-product. The aroma of the product is leek-like and isreminiscent of cabbages and onions. The undertone is woody and green.

EXAMPLE 1 1 In accordance with the procedure of Example 8 car-3-en-5-one is reacted with methylmercaptan by heating the reactionmixture in a suitable pressure-vessel for 3 hours to yield3-methylthio-caran-5-on, boiling point ca 70 at 0.5 mm Hg, n 1.5224.

The odor of the compound is reminiscent of garlic and shallots and has afainter smell of rhubarb and veg- 7 8 etables. As side notes of thearoma the aroma of bal- The o-mercapto-p-menth-8-en-2-one added as asosam, spices and smoke can also be smelt. lution of its crystallineadduct considerably enhanced h d' d th b ff. EXAMPLE 12 t e iffuslon androunde e onquet o Odorant Composition Having a Lavender Note EXAMPLE 14Parts by weight Aromatisatlon of a powdered soup A neutral testingpowdered soup preparation was prepared according to the followingrecipee. 5O o-Mercapto-p-menth-8-en-2-one l()% (in PDE) 100 Spanish WoodOil 450 Lavender Oil Mont Blanc 200 Linalyl acetate 50 Lin-alool l8%NaCl 50 p-tert-Butyl-cyclohexyl-acetate 12% Sugar 5 Coumarin 10% Sodiumglutamate 25 Cinnamyl alcohol synth. 10% hydrolyzed vegetable proteins 5Undecylenaldehyde 10% (in PDE) 50% corn starch 25 Terpineol 15 100% 85Benzyl alcohol 5 l l 4,4-Tetramethyl-6-ethyl-7-acetyll 2,3,4-

tetrahydronaphthalene 1050 PDE =diethylphthalate For the preparation of1 liter neutral-testing soup 45 g of this preparation are necessary. Theaddition of The added 6-mercapto-p-menth-8-en-2-one en- 2,7-3,5g6-methylthio-p-menth-8-en-2-one per lO0lof hanced the diffusion andstren thened the floral in ressou im arted to the neutral-testin sou aleasant g P P P g P P sion of the com osition. omon and leek-taste.

EXAMPLE 13 A X i romatisatlon o mas e otatoes Eau de Cologne Compositionl h p Neutra testin mas ed otatoes are re ared b Parts by Weight: mixingof g p p p y 25 6-Mercapto-p-menth-8-en-2-one 10% (in PDE) 400Bergamotte oil Reggio 3O g pottam flakes 200 Italian Lemon oil g wa 200Californian orange oil 2 5 g l gg met The addition of 3-4 of6-methylthio-p-menth-8-en- 25 fifi oi] Mom Blane 2-one per 100 kg ofmashed potatoes imparted to the g8 t'k iyrf p y CYYSL product aleek-taste; the thiolone (1,5-2 g) in 0,5% 20 gfi i NaCl (100 1 H O)imparted to such solution a predomi- 18 l:|ir4ALdrhyde 1oz Malia l l 2 34 hant note of horseradish and omon.

..,-etramety--ety--acety-,,,- tetrahydronaphthalene What IS clalmfid I 5p-tert:Butyl-alpha-methylhydrocinnamaldehyde l.4-Methylthlo-caran-l-one. Z9 2. 3-methylthio-caran-5-one.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,895,073 Dated 15, 1975 Di 1: L k t l Inventor(s) 6 mar ampars y e a Itis certified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 1, line 15, "captoor" should read capto or Column 4, Example line59, "atm. Is" should read atm. is

. Column 8 Example 14 line 20 "2 ,73,5 g. should read Column 8, Example15, line 32, "34" should read 3-4 g.

Sngncd and Sealed this twenty-first Day Of October 1 975 [SEAL] AfleSt.

RUTH C. M A SON C. MARSHALL DANN Arresting Officer CommissionerufPalents and Trademarks O

1. 4-METHYLTHIO-CARAN-2-ONE.
 2. 3-METHYLTHIO-CARAN-5-ONE.